Safety-fuse.



PATENTED LUGQZO', 190'). sums au F. D. REYNo-L-ns.

SAFETY FUSE.

PPLIOATIOH HL2 un. 22.1906.

UNITED sTATEs PATENT OEEIOE.

JOSEPH-SACHS ND FRANK D. REYNOLDS, OF HARTFORD, CONNECTICUT, ASSIGNORS TO THE SACHS COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CON- a. mi.

NEoTio UT.

Specification of Letters Patent.

SAFETY-FUSE Patented Aug. 20, 1907.

To all iulzom it ymay concern:

Re it known that we, .lossen SACHS and FRANK D. REYNOLDS, both citizens of the United States, and residents of l'Iartford, in the county of Hartford and State of Connecticut, have invented an Improvement in Safety-Fuses, of which the following is a specification.

Oui' present invention relates to safety fuses and particularly tothat class of safety fuses known asinclosed indicating fuses.

Heretofore indicating incloscd fuses have been con strncted commonly comprising a tube or casing, end caps therefor and a strip of fusible metal inclosed Within the casing and electrically connected with said end caps, together with an indicator wire, which latter member is also electrically connected with the end caps and in some instances, is entirely on the outside of the tube or casing, i n Other instances has been passed through the. tube, providing an indicating portion only on the outside of the tube,-and in still other instances, has been entirely within the tube, and means have been in Contact or connected therewith mechanically, or otherwise associated with the same and caused to extend through the casing to the visible surface, indicating the condition of the fusible strip. In fuse devices of this class however, that portion of the indi cator wire extending along the outer surface of the casing or the means associated with the indicator wire mechanically or otherwise employed to show the condition of the fuse strip, have been liable to become broken Or otherwise. impaired, either in transit or from accidental and unobserved causes in the use of the fuse, and it is manifest that when so broken or impaired, the indicating part of the fuse device is incapa 'ble of'perforniing its intended functions.

The object of our present invention is therefore the provision of an indicating safety fuse in which the indicator wire cannot become broken accidentally, or Otherwise impaired, except through the blowing of the fuse and in which the blowing of the fuse is indicated by the rupture of a portion of the casing or tube caused by the rupture of the indicator wire or by the same and means associated therewith.

In carrying out our present invention, we employ a tube or casing suitably provided with an integral Hap,

I end caps or ferrules fitting over the ends of the said tube, a fuse strip within the said tube and electrically connected with the end caps or contact terminals and an indicator wire also electrically connected to the end caps or contact terminals and extending between the saine, and having the indicating portion threaded into and extending wholly within the walls of the tube or casing, as will hereinafter be more particularly de scribed. These ferrules may or may not act as the contact terminals and said indicator wire may be otherwise arranged so as to be ruptured by the current. We preferably place within the easing and in Contact with the fuse strips, insulating filling material in a loose condition.

In the drawing, Figure l is a central longitudinal section of the safety fuse embodying our present in-- vention showing the flat cut made longitudinally of the tube and raised. Fig. 2 is a similar view showing the flap secured in its normal position. Fig. 3 is a .plan view of the structure shown in Fig. 2 with a label placed on the tube. Fig. 4 is a plan view showing a modified form of the flap, in which the flap lifts transversely of the tube. Fig. 5 is a transverse section on dotted line x, zc, Fig. 2. Fig. 6 is a central transverse section illustrating a modified form of the invention on the dotted line y, y, of Fig. 4.

a designates a casing, preferably tubular and made of fiber paper or any suitable insulating material. This casing a is provided with metallic end caps or ferrules b adapted to be secured on the respective ends thereof. c designates fuse strip terminals electrically connected to the end caps b, and d is a. strip of fusible metal extending between and electrically connected with the inner ends of the fuse terminals c. The fusible strip may be made of zinc or similar metal while the strip terminals are usually of less fusible metal such as copper.

As indicated in Figs. l, 2 and 3, the tube or casing a may be provided with a flap 2 formed in the outer surface thereof in any suitable position by cutting or slitting into the walls of the tube. That portion of the tube a beneath the flap 2 is provided with apertures 3 and an indicator wire e, madeof suitable fusible material preferably of higher resistance than the fuse strip is threaded through the apertures 3 and electrically connected at its respective ends with the end caps b, whereupon the flap 2 may be returned to its original position in the tube a, and secured therein by glue, mucilage or other adhesive material. It will thus be seen that the indicating portion c of the indicator wire e extends Wholly within the walls of the tube a and beneath the flap 2 provided therein.

The fiap formed by cutting or slitting the material of the tube, is as thin in sectional area as it can consistently be made to maintain its integrity and its connected relation to the tube. When the cut is made as shown in Figs. 4 and 6, the flap may be so rolled back into position as to obviate the necessity of employing any adhesive material to normally maintain the same in place. It is necessary that the tube be slit sufficiently to provide a covering flap large enough to entirely incase the indicating portion of the indicator Wire Within the walls of the casing.

It will be understood that to insure the point of rupture in the wire being in the `indicating portion thereof, that the resistance of the indicating portion may be increased inany desired manner and also that to insure the raising o i the flap by the` rupture oi the indicator wire, We may employ if found desirable, a grain or two of gunpowder or other explosive Inaterial placed beneath the iap and in connection with or adjacent to the indicating portion of the indicator Wire.

It will also be understood that ii so desired, We may employ a suitable filling material indicated at f of any insulating substance as is common in the art to which this invention pertains, and We may also employ a label or paster 4 having an aperture therein through which the Hap is visible, as shown in Fig. 3, or this label or pastei` may be employed in any desired position on the surface of the tube and may or may not have an aperture therein.

We claiin as our invention:

1. A safetyr fuse comprising a fuse strip, a casing therefor and a wire having an indicating portion extending within the walls of the casing and between the outer and inner surfaces thereof.

2. A safety fuse comprising a fuse strip, a easing therefor and an indicator wire inside the casing and having an indicating portion threaded partially through the casing and extending wholly Within the walls of the same.

3. A safety fuse comprising a fuse strip, a casing therefor, a flap in the said casing and an indicator wire inside the casing and having a portion thereof threaded into and extending beneath the said iiap and wholly within the walls of the casing.

4. A safety fuse comprisingT a fuse strip, a casing therefor, a ap in the said casing and an indicator Wire havingr a portion thereof extending within the Walls of the casing and beneath the said flap and between the outer and inner surfaces of the said walls.

5. safety fuse comprising o. tube, end caps therefor, a fuse strip electrically connected tothe said end caps and an indicator wire inside the said tube and having an indicating portion threaded into and extending wholly within the Walls of the tube.

6. A safety fuse comprising a tube, a flap integral with said tube, end caps for the said tube, a fuse strip electricall)r connected with the said end caps and an indicator wire inside the said tube and having a portion thereof threaded into and extending beneath the said ap and wholly within the Walls of the said tube.

7. A safety fuse comprising a tube, a flap integral therewith and formed by slitting the outer surface thereof, said tube being provided with apertures extending from the inner surface thereof to the under surface of the said [lap` end caps fitting over the extremities of the said tube, a fuse strip electrically connected with the said end caps and an indicator `wire having a portion thereof threaded partially through the said tube and extending beneath the said ap and wholly within the walls of the tube.

8. A safety fuse comprising a fusible conductor, a table of insulating material around said conductor and having an integral dal] on the outer surface and means for moving said ap to indicate the condition of the fusible conductor.

9. A safety fuse comprising a fusible conductor, a tube of insulating material having an integral tiap on its visible surface and means inclosed by the walls of the tube for moving said flap. 

